Karen,
Your concern is exactly the same as mine. In the multi user environment, I have been getting some hang ups, and I want to minimize them. I suppose I could solve the problem by creating some entry in a table at the time any user is doing an update that would alert all other users that they will have to wait a moment and then retry to save their data. But if I can use the power of Rbase to solve the probem for me, I would prefer it.
Mike
-------------- Original message from [email protected]: --------------
Bob: Your explanation sounded very straightforward to me. So if someone
is running with the default, it isn't SPEED that's necessarily the issue. It's
resource conflicts. Is that what you're saying?
I had the following problem at a client just yesterday. A user had an edit form
up and I didn't know it. I was running a program that was doing a multi-row
update on that table. Don't know if it would have updated that particular record,
don't know if that record would have been on the same "page" as my big update.
The update appeared to hang. Kicking her out made the update work.
Assuming that my staticdb and fastlock were both set to ON (they are not at
this client), what would I have set my qualcols to in each program?
Karen
I may be incorrect, but my understanding is that in a heavy multi user environment, if you have
QualCols set to 10 you might be seeing a lot of "resources not available" conflicts. I.E. user
1 does an update and locks up an entire page of data instead of just the one row being updated.
Anyone else accessing the database and happens to select a row in the same page that user 1
has locked will not have access until user 1 releases it. QualCols 2 would be that user 1 locks
only one record thus user 2 would not get locked out unless they access the exact same record.
So if your app is unlikely to access the same "page" of data for updating, even in a heavy multi
user environement, then QualCols 10 would be OK. If your app is constantly updating the same table
and likely records that are in like pages, then QualCols 2 would reduce the number of access conflicts
greatly.
So it all depends on what your app is doing. If only performing looks ups and entering new data 95% of
the time, then QualCols 10 is probably the way to go. If a large number of users are accessing the same data for updates, the QualCols 2 probably is the way to go.
As Razzak mentioned, this can be set "on the fly". However, I must assume that the effect is global.
I.E. is user 1 sets QualCols to 10 and does an update, they will lock out pages of data. Even if user 2 has QualCols 2 (locks single rows) if they try to access data that is in the page of user 1, they will be locked out until the user 1 update completes.
So with all things programming, one must evaluate the environment the app (or command) is going to be used. A scheduled command that runs at 2:00am with no one else on the system could/should have different settings than one running at 10:00am when a hundred users are connected. An app that is 95%
new data entry or lookup would have different settings than an app that is 95% data maintenance.
The QualCols in my opinion is a switch that is available for fine tuning. An update on a single record that uses an index column and a where clause will not have any speed difference if QualCols is set to 10 or 2. An update on 100,000 records without a where clause will have a magnitude difference. So again, it depends on what your app is doing.
Hope that helps.
-Bob
